Action cameras are small, lightweight portable cameras used to take video, still pictures or both. Action cameras are used in action sports, such as hunting, BMX (bicycle motorcross), snow skiing or snowboarding, surfing, car racing, skydiving, etc. The camera is typically mounted so as to point ahead where the operator is going. For example, in bicycling, the camera may be mounted to the handlebars of the bicycle. In snowboarding, the camera may be mounted to the helmet of the snowboarder. In hunting, the camera may be mounted to either the hunter's head or to the hunter's gun.
While many action cameras operate in daylight conditions, there are instances where artificial lighting is desired to supplement low natural light for darkness. For example, hunters hunt at dawn and dusk. In order to avoid scaring wildlife away, infrared lighting is preferred to white light. Therefore, equipping an action camera with infrared lighting is desirable.
Digital cameras use an image sensor to capture the image, whether video or still. Most image sensors react differently to white, or visible, light than to infrared light. In order to compensate, when the image sensor is configured for white light, or daylight, an infrared cut filter is located in-line with the image sensor (between the lens and the image sensor). The infrared cut filter filters out infrared light from the image sensor. When the image sensor is configured for infrared or night conditions, the infrared cut filter is removed from the path of light and a clear, or infrared pass, filter can be put in-line with the image sensor.
In an action camera, several factors, such as weight and power consumption, come in to play when designing a system to remove the infrared cut filter relative to the image sensor.